<?php
	/**
    This file is part of WideImage.
		
    WideImage is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation; either version 2.1 of the License, or
    (at your option) any later version.
		
    WideImage is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.
		
    You should have received a copy of the GNU Lesser General Public License
    along with WideImage; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  **/
	
	class wioCopyChannelsPalette
	{
		static function getInstance()
		{
			static $instance;
			if (!$instance)
				$instance = new wioCopyChannelsPalette();
			return $instance;
		}
		
		function execute($img, $channels)
		{
			$blank = array('red' => 0, 'green' => 0, 'blue' => 0);
			if (isset($channels['alpha']))
				unset($channels['alpha']);
			
			$width = $img->getWidth();
			$height = $img->getHeight();
			$copy = wiPaletteImage::create($width, $height);
			
			if ($img->isTransparent())
			{
				$TRGB = $img->getTransparentColorRGB();
				$newTRGB = $blank;
				foreach ($channels as $channel)
					$newTRGB[$channel] = $TRGB[$channel];
				
				$tci = $copy->allocateColor($newTRGB);
			}
			
			if (count($channels) > 0)
				for ($x = 0; $x < $width; $x++)
					for ($y = 0; $y < $height; $y++)
					{
						$RGB = $img->getRGBAt($x, $y);
						$newRGB = $blank;
						foreach ($channels as $channel)
							$newRGB[$channel] = $RGB[$channel];
						
						$color = $copy->getExactColor($newRGB);
						if ($color == -1)
							$color = $copy->allocateColor($newRGB);
						
						$copy->setColorAt($x, $y, $color);
					}
			
			if ($img->isTransparent())
				$copy->setTransparentColor($tci);
			
			return $copy;
		}
	}
?>